Here is a simple project using an Arduino and some LEDs. What we are going to learn here today is how to make a POV display or Persistence-Of-Vision display. It is made out of just 6$ worth of components. This tutorial gives will teach you how to make a simple and a cheap Arduino POV display. We can use this display as a pocket-sized portable message showing device and tabletop clock.
How Does it Work?
What is POV(Persistence of Vision)? It can be defined in simple words. When a person sees an object, its image remains in the retina of the eye for a time interval of 1/16th of a second. This phenomenon is known as persistence of vision. This phenomenon is used in the POV Display to form images. We turn the LEDs on and off in such a way that the different images overlap each other forming letters. For example:
1 2 3 <– Time
1 1 1 <– Bulb 1
1 0 0 <– Bulb 2
1 1 1 <– Bulb 3
1 0 0 <– Bulb 4
1 1 1 <– Bulb 5
Each row represents the 5 LEDs we use to make the Arduino POV display and each column is a time interval. Each element in the row represents the state of the LED at that given time.
At t = 1 Bulbs 1,2,3,4,5 are ON
At t = 2 Bulbs 1,3,5 are ON
This way we can visually see the letter E formed by the LEDs but the time interval would be very small in milliseconds. Due to the short time intervals and the ability of the LEDs to turn ON and OFF very quickly we can see the letter E as all the 3 images merge. As the motor is spinning and time passes, each LED moves from one position to the next, so all these images merge together.
Required Materials
Tools
- Soldering iron
- Player tool
- Wire cutter
- Glue gun (Not required for the portable device makeover. It is used only for the table top version.)
Electronics
- Arduino Pro Mini
- Female pin socket for Arduino
- Perfboard
- 3V Regulator IC
- 220Ohm Resistors – 5 No.s
- LED – 5 No.s (Although I have shown Green LEDs here, Red is better)
- Old Mobile Battery
Mechanical Parts
- A wooden block / A plastic tin that has little weight
- BO motor 3volt / 12 volt, 500rpm motor
- A wheel of BO motor
- Nut and bolt – 3 pairs
- A scale